Well tools



Oct. 1l, 1966 1'. L. ELLlsToN WELL `TooLs 4 sheets-sheet 1 Filed Dec. 2, 1965 LFE@ 2 INVENTOR. T/homos L. Ellston By/WA/Zn/ ATTORNEYS Oct. ll, 1966 T. L.. ELLlsToN WELL TOOLS 4 Sheets-Sheet 2 Filed Dec. 2. 1963 INVENTOR. Thomas L. Ellison @fl/M7@ @MW f ATTORNEYS Oct. 11, 1966 T. l.. ELLlsToN WELL TOOLS 4 Sheets-Sheet 5 Filed Dec. 2, 1965 [PHG INVENTOR. Thomas L. Ellison ATTORNEYS Oct. ll, 1966 T. L. ELLlsToN WELL TOOLS Filed Doc.

INWLNT( m. Thomas l.. Ellison ATTORNEYS 3,278,219 WELL TOOLS Thomas lL. Elliston, Dallas, Tex.` assignor to Otis Engineering Corporation, Dallas, Tex., a corporation of Delaware Filed Dec. 2, 1963, Ser. No. 327,272 13 Claims. (Cl. 294-8615) This invention relates to well tools and more particularly to a well tool for retrieving objects, such as tubing and the like, from a well.

An object of this invention is to provide a new and improved well tool which is lowerable in a well to engage and grip objects in the well for removing the objects upwardly from the well.

Another object is to provide a retrieving tool having gripping means for engaging an object, such as the upper end of tubing in a well, which gripping means are forced into gripping engagement with the object upon downward movement of the retrieving tool relative to the tubing after the engagement of the retrieving tool therewith and which are also forced and held in gripping engagement with the tubing upon an upward force thereafter being applied to the retrieving tool.

Still another object is to provide a retrieving tool of the character described which is releasable from the object gripped thereby upon limited rotational and then upward movement being imparted to the retrieving tool by means of the pipe by which it is lowered into the well.

A further object is to provide a retrieving tool having hydraulically operated gripping means for engaging and holding an object to be retrieved from a well having release means for releasing the hydraulic pressure holding the gripping means in engagement with the object to be retrieved.

A still further object is to provide a retrieving tool having a pump means including a pump piston and an operator piston movable by lluid pumped by the pump for moving the gripping means into gripping engagement with an object upon downward movement of the retrieving tool relative to the pump piston upon the engagement of the pump piston with an object to be retrieved and having release means for releasing the lluid pressure holding the gripping means in engagement with the object upon a predetermined rotational and longitudinal movement being imparted to the retrieving tool.

Still another object is to provide a retrieving tool of the type described having seal means for sealingly engaging the object being retrieved thereby.

Additional objects and advantages of the invention Will be readily apparent from the reading of the following description of a device constructed in accordance with the invention, and reference to the accompanying drawings thereof, wherein:

FIGURE 1 is a vertical, partly sectional view of the upper portion of a retrieving tool showing it connected to the lower end of a string of pipe by means of which it is lowered into the well;

FIGURE 2 is a view similar to FIGURE 1 being a continuation thereof, and showing the lower portions of the retrieving tool telescoping downwardly over the upper end of a tubing which is to be retrieved from the well;

FIGURE 3 is a vertical, partly section view of the upper portion of the retrieving tool showing the elements of the tool assumed thereby while it is retrieving an ob- 'ect;

l FIGURE 4 is a view similar to FIGURE 3, being a continuation thereof, showing the lower portion of the retrieving tool with the gripping means thereof in gripnited States Patent 3,278,219 Patented Oct. ll, 1966 ICC ping engagement with the tubing being removed from the well;

FIGURE 5 is a fragmentary view showing the slot and pin means for operating the fluid pressure release means of the retrieving tool;

FIGURE 6 is a fragmentary vertical partly sectional view showing the gripping means of the retrieving tool;

FIGURE 7 is a vertical, partly sectional view of the upper portion of the retrieving tool showing the tool immediately after the actuation of the release means for releasing the uid pressure holding the operator piston in operative position and the gripping means in engagement with the tubing;

FIGURE 8 is a view similar to FIGURE 7, being a continuation thereof, showing the lower portion of the retrieving tool;

FIGURE 9 is a fragmentary, vertical partly section view of the lower portion of a modified form of the retrieving tool provided with a sealing means for engaging the tubing; and,

FIGURE l0 is a view simil-ar to FIGURE 9 showing the gripping means and the sealing means of the retrieving tool in engagement with the string of tubing.

Referring now particularly to FIGURES 1 through 8 of the drawings, the retrieving tool 20 embodying the invention includes a tubular body or mandrel 21 having a top section 22 threaded on the lower end of a pipe P by means of which the retrieving tool is movable into and from the Well, a connector or intermediate section 23 threaded in the lower end of the top section and a bottom section 24 threaded in the bottom end of the intermediate section 23. A barrel 25 disposed about the mandrel 21 includes a top section 26, a connector section 27, a lower section 28 and a cam or bowl section 29. The top barrel section is releasably secured to the intermediate mandrel section 23 by a shear screw 32 threaded in the top barrel `section whose inner end extends into a suitable lateral aperture of the intermediate mandrel section. The top barrel section is also connected to the intermediate mandrel section by means of a plurality of pins 33 rigidly secured, as by welding, to the top barrel section which extend into l-slots 34 of an external annular flange 35 of the intermediate mandrel section. Each pin 33 is positioned in the upper end of the short portion 37 of its J-slot so that it engages the downwardly facing arcuate surface 38 dening the upper end of the short leg 37 when the barrel is in the upper position on the mandrel illustrated in FIGURES l and 2 so that a downward force imparted to the mandrel section will not cause shearing of the shear screw 32 and downward movement of the mandrel relative to the barrel assembly.

The mandrel is movable downwardly relative to the barrel, after `the shear screw 32 has been sheared by upward movement of the mandrel relative to the barrel which causes the connection portions 38 of the J-slots to be moved into alignment with the pins 33, upon a rotational movement of the mandrel which moves the long portions 39 of the l-slots into alignment with the pins 33. The external annular llange 40 at the lower end of the intermediate mand-rel section provides an annular upwardly facing shoulder 41 which is engageable with the downwardly facing shoulder 42 provided by the enlargement of the lower portion bore of the barrel section to limit upward movement lof the mandrel -relative to the barrel. The top end of the top barrel section has an internal annular flange 44 provided with an internal annular recess in which is disposed lan O-ring 45 which seals between the flange and the intermediate mandrel section. The O-ring 45 is provided to prevent any foreign material such as sand from entering between the mandrel and the top barrel section which might render difficult or impossible upward movement of the mandrel relative to the barrel section.

The connector barrel section 27 is threaded in the lower end of the top barrel section and has an internal annular flange 46 provided with an annular recess in which is disposed an O-ring 48 which engages the external seal surface 49 of the lower mandrel section below the upper external annular recess 50 thereof.

The lower end portion of the connector barrel section is threaded in the upper end portion of the lower barrel section 28 and is provided with an external annular recess in which is disposed an O-ring 49a which seals between the connector and lower barrel sections.

The mandrel and the top barrel sections are spaced above the connector barrel section to provide an annular passage '51 which is in communication with the exterior through the lateral ports 52 of the top barrel section.

The lower barrel section and the bottom mandrel section are spaced to define an annular pump piston chamber 56 below the connector barrel section in which is slidable a pump 57. The upper end of the pump piston chamber is opened to the exterior through the annular passage 51 and the ports 52 when the mandrel is moved downwardly relative to the barrel to the position illustrated in FIGURE 7 wherein the O-ring 48 is aligned with the recess 50 of the mandrel and out of engagement with the seal surface 49 thereof.

The pump piston has an annular internal groove or recess adjacent its upper end in which is disposed an O- ring 58 which seals between the bottom mandrel section and the pump piston and with an external annular groove in which is disposed an O-ring 59 which seals between the pump piston and the lower barrel section 28 below a lateral portion 62 of a bypass flow passage 63 of the pump piston. The longitudinal portion 64 of the bypass ow passage 63 opens downwardly through the orifice 65 of a spring retainer 66 threaded in the lower end of the .longitudinal portion. A spring 67 disposed in the longitudinal -portion of the flow passage biases a ball check valve 68 against an annular seat 69 of the pump piston, its upper end bearing against the ball check valve and its lower end against the retainer.

The ball check valve at all times prevents upward flow of liquid through the bypass fiow passage 63 and prevents downward flow therethrough until the pressure in the upper chamber 56 above the pist-on 57 has increased to .a value suficiently great to overcome the force exerted by the spring 67 on the ball valve. Liquid, such as oil, may be introduced into the pump piston charnber above the pump piston in any desired manner as through an inlet port 70 of the connector barrel section which is closable by a suitable plug 71.

The upward movement of the pump piston in the chamber 56 is limited by the engagement of its upper annular end surface or shoulder 74 with the annular bottom end shoulder 75 of the connector barrel section.

A latch or pawl 77 disposed in a suitable external recess 78 of the top pump piston section 57 is pivotally secured to the pump piston, as at 79, and is biased outwardly by a leaf spring 80. The lower end of the latch or pawl 77 enters into the internal annular latch recess 82 of the lower barrel section when the pump piston is moved to its uppermost position relative to the barrel and engages the lower upwardly facing annular shoulder 83 of the lower barrel section 28 to latch Ithe pump piston against subsequent downward movement relative to the barrel. Downward movement of the pump piston relative to the barrel is limited by the engagement of its lower end with the upwardly facing annular shoulder 84 of the lower barrel section 28.

A dependent sleeve 88 has a reduced upper end portion 89 threaded into the lower end of the pump piston. An O-ring 91 disposed in a suitable annular external recess of the pump piston seals between the piston and the sleeve.

The external surface 93 of the sleeve is of greater radius than the external surface 49 of the bottom mandrel section 24 and, therefore, the volume Iof the upper portion of the pump piston chamber above the O-ring 59 decreases more rapidly than the volume of the lower portion of the pump piston chamber below the O-ring 59 which increases as the barrel and mandrel is moved downwardly relative to the pump piston when the pump piston is held against downward movement. Liquid then pumped from the pump piston chamber is forced into the upper end of the annular operator piston chamber 95 defined by the internal surface 96 of the lower barrel section below its shoulder 84 and the external surface 93 of the sleeve.

An operat-or piston is slidably disposed in the operator piston chamber and has O-riings 101 and 102 disposed in suitable external and internal recesses thereof which engage the internal and external surfaces 96 and 93, respectively. The operator piston has a plurality of dependent resilient collet fingers 105 whose lower ends are provided with inner serrations or teeth 106 and with external bosses 107. The bosses have outer cam surfaces 108 inclined downwardly and inwardly and are engageable with the .internal downwardly and inwardly extending or beveled cam surface 109 of the bottom or bowl barrel section 29. The external bosses of the fingers are receivable in the lower enlarged portion 110 of the bore or passage of the lower barrel section 29 which permits the collet fingers to assume their inoperative outer positions, illustrated in FIGURE 2, when the operator pistion is in its upper position relative to the barrel illustrated in FIGURE 2.

The pump piston `sleeve 88 has an external outer flange 112 providing an upwardly facing external annular shoulder 113 which is engageable with the downwardly facing internal shoulder 114 of the operator piston to limit downward movement of the operator piston relative thereto. The bottom or bowl barrel section 29 has an upwardly and inwardly inclined cam or beveled surface 115 for camming or guiding the barrel over the upper end of an object such as the tubing T which is to be removed from the well while the sleeve 88 has a similar upwardly and inwardly inclined or beveled shoulder 118 which is engageable with the upper end of such object as the tubing.

In use, when an object is to be retrieved or removed from a well, for example, the tubing T whose upper end portion may have broken off in the well, the retrieving tool 20, with its operative elements in the positions shown in FIGURES l and 2, is secured to the lower end of a string of pipe P. The operator piston 100 is now in its upper position wherein its annular top end surf-ace engages the annular bottom end surface of the pump piston 57 so that the external bosses 107 of the collet fingers lare in the enlarged portion 110 of the bore of the lower barrel section and the collet fingers are in their outer inoperative positions in the barrel illustrated in FIGURE 2. An incompressible fiuid, such as oil, is introduced into the top portion of the upper pump piston chamber 56 above the pump piston through the filler port 70 t-o fill the pump piston chamber above the pump piston which is then in its lowermost position in the barrel. The plug 71 is then threaded in the filler port to close it. The ball check valve 68 now prevents flow of the oil from the top portion of the chamber 56 above the pump piston to the lower end of the chamber through the bypass fiow passage 63 due to the force exerted thereon by the spring 67 and the operator piston -is held against downward movement in the barrel since any downward movement thereof in the barrel tends to create a va-cuum in the chamber 56 below the pump piston. In addition, the collet fingers 105 tend to hold the operator piston in its upper position illustrated in FIGURE 2 due to the engagement of the cam surfaces 108 thereof with the cam surface 109 of the barrel and the resilient force with which the collet fingers resist inward flexing or movement. The operator piston is thus held in its uppermost position against any `accidental downward movement in the barrel and the collet fingers remain in their outer inoperative positions during lowering of the retrieving tool in the well. The barrel is now held in its upper position on the mandrel 21 by the shear screw 32. The pins 34 are in the upper ends of the short portions 37 of the J-slots and engage the downwardly facing surfaces 38 defining the upper ends of the short portions.

The retrieving tool is then lowered into the well on the string of pipe P until the lower end of the barrel telescopes the upper end of the object which is to be retrieved, such as the upper end of the tubing T. The cam surface or shoulder 115 of the bott-o-m barrel section 29 guides downward movement of the mandrel over the upper end of the tubing. As the retrieving tool telescopes over the upper end portion of the -tubing and the collet fingers move downward thereabout, their teeth or serrations 106 do not grippingly engage the outer surface of the tubing since the lower ends of the collet lingers are now in their outer inoperative position. The retrieving tool is moved downwardly over the upper end port-ion of the tubing until the top end of the tubing engages the bottom surface 118 of the pump piston sleeve 83 which is beveled inwardly and upwardly to help center the retrieving tool on the tubing as it is lowered thereon. When the sleeve 88 engages the upper end of the tubing, further downward movement of the pump piston is arrested.

A further downward force imparted to the pipe P at the `surface now causes the mandrel 21 and barrel 25 to move downwardly relative to the pump piston 57 and the incompressible liquid in the pump piston chamber- 56 above the pump piston is forced downwardly through the bypass flow passage 63 into the lower portion of the pump piston chamber below the pump piston and into the upper end of the operator piston cha-mber 95 above the operator piston 100. The crosssectional area of the operator piston chamber 95 is substantially smaller than that of the lower portion of the pump piston chamber so that the lliquid pumped through the bypass flow passage 63 past the check valve 68 into the upper end of the operator piston chamber causes the operator piston to move downwardly relative to the barrel. Downward movement of the operator piston relative to the barrel causes the lower ends of the collet fingers to be moved inwardly due to the camming engagement lof the cam surfaces 108 with the cam surface 109 of the bottom or bowl barrel section 29 .and their teeth or serrations 106 engage the external surface of the tubing T and dig thereinto. The pawl or pawls 77 do not prevent such downward movement of the barrel relative t-o the pump piston since the barrel slides downwardly past the surfaces of the pawl or pawls which are biased yagainst the internal surfaces of the lower barrel section 28 by the spring 80.

When further downward movement of the mandrel and barrel is arrested as the lower ends of the collet fingers reach the limit of their inward movement after their teeth have dug into the tubing, an upward force is imparted to the string of pipe P at the surface and the upward force applied thereby to the man-drel may now cause the shear pin 32 to shear since such force tends to move the barrel upwardly but such upward movement of the barrel is now resisted by the weight of the tubing or any force resisting its upward movement. It will be apparent that such upward movement of the mandrel is limited by the engagement of the shoulder 41 of the mandrel with the shoulder 42 of the barrel. Further upward movement then imparted to the pipe P causes an upward force to be exerted on the tubing T which is then moved upwardly to the .surface by means of the retrieving tool.

It will be apparent that the greater force necessary to move the tubing upwardly, the greater will be the force with which the serrations or teeth 106 of the collet fingers are hel-d in gripping engagement with the tubing due to the camming engagement between the cam surface 109 of the barrel and the cam surface 108 of the collet lingers. The tubing is thus held against downward movement relative to the barrel and will be raised by the retrieving tool as the string of pipe is raised upwardly to the surface.

Should it be desired to disengage the retrieving tool from the tubing before it has been pulled upwardly to the surface after the teeth or serrations 106 of the collet iingers have `been moved into gripping engagement with the tubing, the pipe P is first pulled up to position the connecting portions 38 of the J-slots in alignment with the pins 33, then rotated to the right, as seen in FIGURE 5, to move the lower ends of the long portions or legs 39 of the J-slots into alignment with their pins 33, and then downwardly to cause the mandrel to move downwardly relative to the barrel until such downward movement of the mandrel moves the sealing surface 49 downwardly below the O-ring 48 and out of sealing engagement therewith so that the fluid trapped in the upper portion of the pump piston chamber 56 above the pump piston is free to flow outwardly -of the barrel through the annular passage 51 and the ports 52. Such downward movement of the mandrel relative to the barrel and to the pump piston is continued until the lower end shoulder of the mandrel engages the annular end shoulder 116 of the connector barrel `section 27 or until the downwardly facing bottom end shoulder 122 of the top mandrel section engages the annular top shoulder 119 of the top barrel section, whichever occurs sooner. Further downward movement of the pipe P now causes the barrel to move downwardly with the mandrel relative to the pump and operator pistons, the oil in the pump piston chamber above the pump piston flowing to the exterior as the volume of the pump piston chamber `above the pump piston is decreased. The barrel and mandrel are now moved downwardly relative to the pump piston until the upper end shoulder 74 of the pump piston is engaged by the shoulder 75 of the barrel connector section 27. During such downward movement of the barrel, its cam surface 109 is moved downwardly relative to the collet fingers and their cam surfaces 108 so that the collet fingers are freed to move outwardly to their outer positions due to their resilient force of the collet fingers. When the barrel is moved to its Lowermost position relative to the .pump piston, illustrated in FIGURE 7, the pawl or pawls 77 are in alignment with the internal annular recess 82 and move outwardly thereinto. An upward pull may now be imparted to the mandrel through the pipe and causes its shoulder 41 to engage the shoulder 42 of the barrel to cause the barrel to move upwardly with the mandrel. Upward movement of the barrel now causes the pump piston to move upwardly therewith due to the engagement of the pawl or pawls 77 with the shoulder 83. Upward movement of the pump piston and barrel now causes upward movement of the operator piston due to the engagement of the shoulder 113 of the sleeve with the shoulder 114 of the operator piston which takes place before the barrel cam surface 109 can again engage the cam surfaces 108 of the collet fingers. The retrieving tool is thus released from engagement with the tubing T and may be removed from the well leaving the tubing in the well.

It will now be seen that a new and improved retrieving tool 20 has been illustrated and described which has gripping means which inherently resiliently tend to remain in their outer inoperative positions and which are movable into gripping engagement with an object to be removed from a well by hydraulic means which includes the pump and operator pistons 57 and 100.

It will further be seen a retrieving tool includes a mandrel having a barrel disposed thereabout providing an annular pump pist-on chamber 56 closed at its upper end in which an annular pump piston is slidable and that the pump piston and the barrel have means providing another annular ypiston Ichamber 95 which communicates with the lower end of the pump piston chamber and in which an operator piston is slidably disposed.

It will further be seen that the retrieving tool is provided with a bypass flow passage 63 communicating the upper end portion of the pump piston chamber above the pump piston with the lower end portion thereof below the pump piston and that a check valve 68 prevents fiow of uid through the bypass passage from the lower end portion of the pump piston chamber to the upper end portion thereof.

It will further be seen that downward movement of the mandrel and the barrel relative to the pump ypiston causes liquid to be forced or pumped from the upper end of the pump piston chamber to the lower end thereof and into the upper end of the operator piston chamber due to the difference in the cross-sectional areas of the pump piston chamber above and below the pump piston, the crosssectional area of the pump piston chamber below the pump piston being smaller than the cross-sectional area of the pump piston chamber above the pump piston.

It will further be seen that the operator piston is moved downwardly relative to the barrel by liquid pumped into the upper end of its chamber and that the operator piston has gripping means which are movable into gripping engagement with an object positioned therebetween by co-engageable means of the barrel and the gripping means upon downward movement of the operator piston relative to the mandrel.

It will further be seen that the mandrel and the barrel have valve or seal means, the seal surface 49 and the O- ring 48, which close the upper end of the pump piston chamber and which open the top end of the pump piston chamber to the exterior of the barrel upon downward movement of the mandrel relative to the barrel, and that the barrel and the mandrel have co-engageable means which permits such downward movement of the mandrel relative to the barrel only upon a predetermined longitudinal upward movement and a predetermined rotational movement of the mandrel relative to the barrel.

It will further be apparent that the barrel and the mandrel may be moved downwardly relative to the pump piston after such predetermined downward movement of the mandrel relative to the barrel to move the co-engageable means of the gripping means and of the barrel out of engagement with one another to permit the gripping means to move out of gripping engagement with the object held therebetween.

Referring now particularly to FTGURES 9 and 10 of the drawings, the retrieving tool 150 is similar to the retrieving tool and, accordingly, the elements of the retrieving tool 150 have been provided with the same reference numerals, to which the subscript a has been added, as the corresponding elements of the well tool 20. The well tool 150 differs from the retrieving tool 20 by having a resilient tubular seal member 151 disposed in the lower barrel section 28a above the bottom barrel section 29a. An annular cam of bowl member 152 having an inwardly and downwardly beveled shoulder or surface 109a engageable by the downwardly and inwardly beveled surfaces 108@ of the collet fingers 105e is disposed above the resilient sealing element 151 and its annular end surface or shoulder 153 engages the annular top end surface 154 of the resilient seal element. Upward movement of the annular bowl member 152 is limited by the engagement of the top annular shoulder of its external annular liange 155 with the bottom shoulder of the internal fiange 157 of the lower barrel section 28a. Downward movement of the resilient tubular seal member 151 is limited by the engagement of its annular bottom end surface or shoulder 158 with the top end annular shoulder or surface 159 of the bottom barrel section 29a. The resilient member is provided at its top and bottom with annular garter spring type members 160 and 161 which are molded to the body of the seal member 151 and which deform to bridge the gaps between the external surface of the object to be retrieved, such as the tubing T, and the internal surfaces of the bottom barrel section 29a and the bowl member 152 when the resilient member is compressed to limit extrusion of the resilient substance of the seal member into the gaps.

It will be apparent that when the downward movement of the sleeve 88a, and therefore of the pump piston of the retrieving tool is stopped by the engagement of the shoulder 11-8a of the sleeve 88a with the top end surface of the tubing T, further downward movement of the barrel 25a causes liquid under pressure to be pumped into the operator piston chamber a above the operator piston a and the operator piston is moved downwardly relative to the barrel. As the operator piston is moved downwardly relative to the barrel, the collet fingers first exert a downward force on the bowl member 152 and tend to move it downwardly in the lower barrel section against the resilinet force of the seal member 151 which is thus compressed and expanded into sealing engagement with the tubing. When downward movement of the bowl member is stopped, when the resilient member is fully compressed and in sealing engagement with the tubing, further downward movement of the piston 100a and the collet fingers causes the lower ends of the collet fingers to be cammed inwardly due to the camming engagement of their surfaces 108a with the cam surfaces 109a of the now stationary bowl member 152 so that their serrations or teeth 106a grippingly engage the external surfaces of the tubing.

It will be apparent that when an upward force is then exerted on the bowl 29a the seal member is held compressed and the lower ends of the collet fingers are biased inwardly into gripping engagement with the tubing T so that the greater force with which the tubing T resists upward movement, the greater the force with which the seal member 151 and the gripping means or collet fingers of the retrieving tool are held in sealing and gripping engagement with the tubing T.

yIt will now be apparent that the retrieving tool functions in the same manner as the retrieving tool 20 but in addition has a sealing means providing a fluid type seal between the object to be retrieved and if desired, liuids may be pumped into or from the tubing T being retrieved through the retrieving tool and through the string of pipe by means of which a retrieving tool is lowered into and raised from the well.

The foregoing description of the invention is explanatory only, and changes in the details of the construction illustrated may be made by those skilled in the art, within the scope of the appended claims, with-out departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A well tool including: a tubular mandrel; a barrel disposed about said tubular mandrel and providing with said tubular mandrel an annular upper piston chamber; an annular pump piston longitudinally movable in said chamber and having means providing with said barrel a lower annular chamber whose upper end is in communication with the lower end of said upper chamber by a bypass flow passage; an annular operator piston longitudinally movable in said lower chamber, said operator piston being movable downwardly in said lower chamber relative to said barrel upon downward movement of said mandrel and said barrel relative to said pump piston by liquid displaced from the upper end portion of said upper chamber by such downward movement of said mandrel and said barrel relative to said pump piston, said piston having means engageable with an object extending upwardly in said barrel for preventing downward movement of said pump piston relative to the said object; gripping means disposed in said barrel and operable by said operator piston for engaging an object extending upwardly into said mandrel, said gripping means and said barrel having cao-engageable means for moving said gripping means inwardly to engage an object in said barrel upon downward movement of said operator piston relative .to said barrel, said barrel and said mandrel having co-engageable means for controlling movement of said mandrel relative to said barrel, said barrel and said mandrel having means closing the upper end of said upper chamber, said last mentioned means opening the upper end of said upper chamber to the exterior of the well tool upon predetermined rotational movement of said mandrel relative to said barrel to permit downward movement of said mandrel relative to said barrel and said pump piston to free said gripping means for movement out of engagement with an object held thereby whereby said retrieving tool is releasable from an object previously engaged thereby.

2. A well tool including: a tubular mandrel; a barrel disposed about said tubular mandrel and providing with said tubular mandrel an annular upper piston chamber; an annular pump piston longitudinally movable in said chamber and having means providing with said barrel a lower annular chamber whose upper end is in communication with the lower end of said upper chamber by a bypass flow passage; an annular operator piston longitudinally movable in said lower chamber, t-he cross-sectional area of the upper end of said upper chamber being greater than the cross-sectional area of the lower end of said upper chamber whereby downward movement of said barrel and mandrel causes liquid to be pumped from the upper end of said upper chamber into the upper end of said lower piston chamber, said lower chamber having a smaller cross-sectional area than the lower end portion of said upper chamber whereby said operator piston is m-oved downwardly relative to said barrel by liquid pumped into said lower chamber upon downward movement of said mandrel and barrel relative to said pump piston; gripping means disposed in said barrel and operable by said operator piston for engaging an object extending upwardly into said mandrel, said gripping means and said barrel having co-engageable means for moving said gripping means inwardly to engage an object in said barrel upon downward movement of said operator piston relative to said barrel, said barrel and said mandrel having co-engagcable means for controlling movement of said mandrel relative to said barrel, said barrel and said mandrel having means closing the upper end of sai-d upper chamber, said last mentioned means opening the upper end of said upper chamber to the exterior of the well tool upon predetermined rotational and longitudinal movement of said mandrel relative to said barrel to permit downward movement of said barrel relative to said pump piston to free said gripping means for movement out of engagement with an object held whereby said retrieving tool is releasable from an object previously engaged thereby.

3. A well tool including: a tubular mandrel; a barrel disposed about said tubular mandrel and providing with said tubular mandrel an annular upper piston chamber; an annular pump piston longitudinally movable in said chamber and having means providing with said barrel a lower annular chamber whose upper end is in communication with the lower end of said upper chamber by a bypass flow passage; an annular operator piston being movable downwardly in said lower chamber relative to said barrel upon downward movement of said mandrel and said barrel relative to said pump piston by liquid disposed from the upper end of said upper chamber by such downward movement of said mandrel and said barrel relative to said pump piston, said pump piston having means engageable with an object extending upwardly in said barrel for preventing downward movement of said pump piston relative to the said object; gripping means disposed in said barrel and operable by said operator piston for engaging an object extending upwardly into said mandrel, said gripping means and said barrel having co-engageable means for moving said gripping means inwardly to engage an object in said barrel upon downward movement of said operator piston relative to said barrel, said barrel and said mandrel having c2c-engageable means for controlling movement of said mandrel relative to said barrel, said barrel and said mandrel having means closing the upper end of said upper chamber, said last mentioned means opening the upper end of said upper chamber to the exterior of the well tool upon predetermined movement of said mandrel relative -to said barrel to permit downward movement of said Abarrel relative to said pump piston to free said gripping means for movement out of engagement with an object held thereby whereby said retrieving tool is releasable from an object previously engaged thereby upon a predetermined movement of said mandrel relative to said barrel, said pump piston and said barrel having means co-engageable when said barrel is in a lowermost position relative to said pump piston wherein said gripping means are free to move out of engagement with an object disposed therebetween and upward movement of said barrel relative yto said pump piston is limited.

4. A well tool including: a tubular mandrel; a barrel disposed about said tubular mandrel and providing with said tubular mandrel an annular upper piston chamber; an annular pump piston longitudinally movable in said chamber and having means providing with said barrel a lower annular chamber whose upper end is in communication with the lower end of said upper chamber by a by-pass flow passage; an annular operator piston being movable downwardly in said lower chamber relative to said barrel upon downward movement of said mandrel and said barrel relative to said pump piston by liquid disposed from the upper end of said upper chamber by such downward movement of said mandrel and said barrel relative to said pump piston, said pump piston having means engageable with an object extending upwardly in said barrel for preventing downward movement of said pump piston relative t-o lthe object; gripping means disposed in said barrel and operable by said opera-tor piston for engaging an object extending upwardly into said mandrel, said gripping means and said barrel lhaving coengageable means for moving said gripping means inwardly to engage an object in said barrel upon downward movement of said operator piston relative to said barrel, said b-arrel and said mandrel having co-engagebale means for controlling movement of said mandrel relative to said barrel, said barrel and said mandrel having means closing the upper end of said upper chamber, said last mentioned means opening the upper end of said upper chamber to the exterior of the well tool upon predetermined rotational and longitudinal movement of said mandrel relative to said barrel to permit downward movement of said barrel relative to said pump piston Ito free said gripping means for movement out of engagement with an object held thereby whereby said retrieving tool is releasable from an object previously engaged thereby upon a predetermined movement of said mandrel relative to said barrel, said pump piston and said barrel having means co-engageable when said barrel is in a lowermost position relative to said pump piston wherein said gripping means are free to move out of engagement with an object disposed therebetween and upward movement of said barrel relative to said pump piston is limited, said pump piston and said operator piston having co-engageable means limiting upward movement of said pump piston relative to said operator piston.

5. A well tool including: a tubular mandrel; a barrel disposed about said tubular mandrel and providing with said tubular mandrel an annular upper piston chamber; an annular pump piston longitudinally movable in said chamber and having means providing with said barrel a lower annular chamber whose upper end is in communication with Ithe lower end of said upper chamber by a by-pass o'w passage; an annular operator piston longitudinally movable in said lower chamber, the crosssectional area of the upper end of said upper chamber being greater than the cross-sectional area of the lower end of said upper chamber whereby downward movement of said barrel and mandrel causes liquid to be pumped into the upper end of said lower piston chamber, said lower chamber having a smaller cross-sectional area than the lower end of said upper chamber whereby said operator piston is moved downwardly relative to said barrel by liquid pumped into said lower chamber by the downward movement of said mandrel and barrel relative to said pump piston; gripping means disposed in said barrel and operable by said operator piston for engaging an object extending upwardly into said mandrel, said gripping means and said barrel having tto-engageable means for moving said gripping means inwardly to engage an object in said barrel upon downward movement of said operator piston relative to said barrel, said barrel and said mandrel having co-engageable means for controlling movement of said mandrel relative to said barrel, said barrel and said mandrel having means closing .the upper end of said upper chamber, said last mentioned means opening the upper end of said upper chamber to the exterior of the well tool upon predetermined rotational and longitudinal movement of said mandrel relative to said barrel to permit downward movement of said barrel relative to said pump piston to free said gripping means for movement out of engagement with an object held thereby whereby said retrieving tool is releasable from an object previously engaged thereby upon a predetermined movement of said mandrel relative to said barrel, said pump piston and said barrel having means co-engageable when said barrel is in a lowermost position relative to said pump piston and said gripping means are free to move out of engagament with an object disposed therebetween and upward movement of said barrel relative to said pump piston is limited.

6. A well tool including: a tubular mandrel; a barrel disposed about said tubular mandrel and providing with said tubular mandrel an annular upper piston chamber; an annular pump piston longitudinally movable in said chamber and having means providing with said barrel a lower annular chamber whose upper end is in communication with the lower end of said upper chamber by a bypass ow passage; an annular operator piston longitudinally movable in said lower chamber, the cross-sectional area of the upper end of said upper chamber being greater than the cross-sectional area of the lower end of said upper chamber whereby downward movement of said barrel and mandrel causes liquid to be pumped into the upper end of said lower piston chamber, said lower charnber having a smaller cross-sectional area than the lower end of said upper chamber whereby said operator piston is moved downwardly relative to said barrel by liquid pumped into said lower chamber by the downward movement of said mandrel and barrel relative to said pump piston; gripping means disposed in said barrel and operble by said operator piston for engaging an object extending upwardly into said mandrel, said gripping means and said barrel having co-engageable means for moving said gripping means inwardly to engage an object in said barrel upon downward movement of said operator piston relative to said barrel, said barrel and said mandrel having co-engageable means for controlling movement of said mandrel relative to said barrel, said barrel and said mandrel having means closing the upper end of said upper chamber, said last mentioned means opening the upper end of said upper chamber to the exterior of the well tool upon predetermined movement of said mandrel relative to said barrel to permit downward movement of said barrel relative to said pump piston to free said gripping means for movement out of engagement with an object held thereby whereby said retrieving tool is releasable from an object previously engaged thereby upon a pre- (determined movement of said mandrel relative to said barrel, said pump piston and said barrel having means coengageable when said barrel is in a lowermost position relative to said pump piston wherein said gripping means are free to move out of engagement with an object disposed therebetween and upward movement of said barrel relative to said pump piston is limited, said pump piston and said operator piston having co-engageable means limiting upward movement of said pump piston relative to said operator piston.

7. A well tool including: a tubular mandrel; a barrel disposed about said tubular mandrel and providing with said tubular mandrel an annular upper piston chamber; an annular pump piston longitudinally movable in said chamber and having means providing with said barrel a lower annular chamber whose upper end is in communication with the lower end of said upper chamber by a bypass ow passage; check valve means preventing fluid ow through said bypass flow passage from the lower end of the upper chamber to the upper end thereof; an annular operator piston longitudinally movable in said lower chamber, said operator piston being movable downwardly in said lower chamber relative to said barrel upon downward movement of said mandrel and said barrel relative to said pump piston by liquid displaced from the upper end of said upper chamber by such downward movement of said mandrel and said barrel relative to said pump piston, said piston having means engageable with an object extending upward in said barrel for preventing downward movement of said pump piston relative to the said object; gripping means disposed in said barrel and operable by said operator piston for engaging an object eX- tending upwardly into said mandrel, said gripping means and said barrel having co-engageable means for moving said gripping means inwardly to engage an object in said barrel upon downward movement of said operator piston relative to said barrel, said barrel and said mandrel having co-engageable means for controlling movement of said mandrel relative to said barrel, said barrel and said mandrel having means closing the upper end of said upper chamber, said last mentioned means opening the upper end of said upper chamber to the exterior of the well tool upon predetermined rotational movement of said mandrel relative to said barrel to permit downward movement of said mandrel relative to said barrel and said pump piston to free said `gripping means for movement out of engagement with an object held thereby whereby said retrieving tool is releasable from an object previously engaged thereby.

8. A well tool including: a tubular mandrel; a barrel disposed about said tubular member and providing with said tubular mandrel an annular upper piston chamber; an annular pump piston longitudinally movable in said chamber and having means providing with said barrel a lower annular chamber whose upper end is in communication with the lower end of said upper chamber by a bypass flow passage; an annular operator piston longitudinally movable in said lower chamber, said piston being movable downwardly in said lower chamber relative to said barrel upon downward movement of said mandrel and said barrel relative to said pump piston by liquid displaced from the upper end of said upper chamber, said pump piston having means engageable with an object eX- tending upwardly in said barrel for preventing downward movement of said pump piston relative to the object; and gripping and sealing means disposed in said barrel and operable by said operator piston for engaging an object extending upwardly into said mandrel and sealing between said barrel land the object upon downward movement of said operator piston relative to said barrel.

9. A well tool including: a tubular mandrel; a barrel disposed about said tubular member and providing with said tubular mandrel an annular upper piston chamber; an annular pump piston longitudinally movable in said chamber and having means providing with said barrel a lower annular chamber whose upper end is in communication with the -lower end of said upper chamber by a bypass flow passage; an annular operator piston longitudinally movable in said lower chamber, said operator piston being movable downwardly in said lower chamber relative to said barrel upon downward movement of said mandrel and said barrel relative to said pump piston by liquid displaced from the upper end of said upper chamber, said pump piston having means engageable with an object extending upwardly in said barrel for preventing downward movement of said pump piston relative to the object; and gripping and sealing means disposed in said barrel and operable by said operator piston for engaging an object extending upwardly into said mandrel and sealing between said barrel and the object upon downward movement of said operator piston relative to said barrel; said barrel and said mandrel having co-engageable means for contr-olling movement of said mandrel relative to said barrel, said barrel 4and said mandrel having means closing the upper end of said upper chamber, said last means opening the upper end of the upper chamber to the exterior of the well tool upon predetermined rotational movement of said mandrel relative to said barrel to permit downward movement of said mandrel relative to said barrel and said pump piston to free said gripping means for movement out of engagement with an object held thereby whereby said retrieving tool is releasable -from an object previously engaged thereby.

10. The well tool `of claim 9, wherein said seal .and gripping means includes -a tubular seal element disposed in said bar-rel against downward movement therein; annular means disposed in said barrel and engageable with the upper end of said seal element and movable downwardly in said barrel, said annular means including `a cam surface; and resilient gripping means carried 'by said operator piston having cam surfaces engageable with lsaid cam surface whereby downward movement of said operator piston causes downward movement of said annular means to cause said seal element to be expanded into sealing engagement with an object disposed inwardly therein and causes said gripping means to be moved inwardly into gripping engagement with the object.

11. The well tool of claim 8, wherein said seal and gripping means includes a tubular seal element disposed in said barrel against downward movement therein; annular means disposed in said barrel and engageable with the upper end of said seal element and movable down- Wardly in said barrel, said annular means including a cam surface; and resilient gripping means carried by said `operator piston having cam surfaces engageable with said cam surface whereby downward movement of said operator piston causes downward movement of said annular means to cause said seal element to be expanded into sealing engagement with an object disposed inwardly therein and causes said gripping means to be moved inwardly into gripping engagement with the object.

12. A well tool including: a tubular member providing `an .annular piston chamber closed at its upper end; an annular pump piston disposed in the lower portion of said pump piston chamber `and having bypass flow means Icommunicating the upper end of said chamber to the lower end thereof, said pump piston having engaging means extending downwardly in said tubular member and engageable Iwith an object extending upwardly thereinto whereby downward movement of said tubular member causes liquid to be forced out of said upper chamber through said bypass flow passage upon downward movement of the tubular member relative to the pump piston when downward movement of the pump piston is arrested by the engagement of its engaging means with an `object extending into the said tubular member, said tubu- Ilar member and said pump piston providing a second annular piston chamber, and operator piston slidably mounted in said chamber and positioned in the upper position therein, said tubular member and said operator piston having co-engageable means for grippingly engaging an object extending into the barrel when said operator piston is moved downwardly in said tubular member by iluid forced from said upper chamber into said lower chamber, said tubular member including a barrel section and a mandrel section movable longitudinally with respect to each other and having means for opening the upper end of said closed chamber upon predetermined longitudinal movement of said mandrel section relative to said barrel section of said tubular member.

13. A well tool including: a tubular member providing an annular piston chamber closed at its upper end; an annulfar pump piston disposed in t-he lower portion of said pump piston chamber and having bypass flow means communicating the upper end of lsaid chamber to the lower end thereof, said pump piston having engaging means extending downwardly in said tubular member and engageable with an object extending upwardly thereinto whereby downward movement of said tubular member causes liquid to be forced out of said -upper chamber through said bypass flow passage upon downward movement of the tubular member relative to the pump piston when downward movement of the pump piston is arrested by the engagement of its engaging means with an object extending into said tubular member, said tubular member and said pump piston providing a second annular piston chamber, an operator piston slidably mounted in said chamber and positioned in the upper position therein, said tubular member and said operator piston having coengageable means for grippingly engaging an object extending into the barrel When said operator piston is moved downwardly in said tubular member by fluid forced from said upper chamber into said lower chamber, said tubular member having means for opening the upper end of said closed chamber, said tubular member including a barrel section `and a mandrel section; and co-engageable means on said sections for controlling longitudinal movement of said sections relative to one another, said opening means being opened upon predetermined down- Ward movement of said mandrel section relative to said barrel section.

References Cited by the Examiner UNITED STATES PATENTS 3,208,788 9/1965 Roark 294-86.l5

GERALD M. FORLENZA, Primary Examiner.

G. F. ABRAHAM, Assistant Examiner. 

1. A WALL TOOL INCLUDING: A TUBULAR MANDREL; A BARREL DISPOSED ABOUT SAID TUBULAR MANDREL AND PROVIDING WITH SAID TUBULAR MANDREL AN ANNULAR UPPER PISTON CHAMBER; AN ANNULAR PUMP PISTON LONGITUDINALLY MOVABLE IN SAID CHAMBER AND HAVING MEANS PROVIDING WITH SAID BARREL A LOWER ANNULAR CHAMBER WHOSE UPPER END IS IN COMMUNICATION WITH THE LOWER END OF SAID UPPER CHAMBER BY A BYPASS FLOW PASSAGE; AN ANNULAR OPERATOR PISTON LONGITUDINALLY MOVABLE IN SAID LOWER CHAMBER, SAID OPERATOR PISTON BEING MOVABLE DOWNWARDLY IN SAID LOWER CHAMBER RELATIVE TO SAID BARREL UPON DOWNWARD MOVEMENT OF SAID MANDREL AND SAID BARREL RELATIVE TO SAID PUMP PISTON BY LIQUID DISPLACED FROM THE UPPER END PORTION OF SAID UPPER CHAMBER BY SUCH DOWNWARD MOVEMENT OF SAID MANDREL AND SAID BARREL RELATIVE TO SAID PUMP PISTON, SAID PISTON HAVING MEANS ENGAGEABLE WITH AN OBJECT EXTENDING UPWARDLY IN SAID BARREL FOR PREVENTING DOWNWARD MOVEMENT OF SAID PUMP PISTON RELATIVE TO THE SAID OBJECT; GRIPPING MEANS DISPOSED IN SAID BARREL AND OPERABLE BY SAID OPERATOR PISTON FOR ENGAGING AN OBJECT EXTENDING UPWARDLY INTO SAID MANDREL, SAID GRIPPING MEANS AND SAID BARREL HAVING CO-ENGAGEABLE MEANS FOR MOVING SAID GRIPPING MEANS INWARDLY TO ENGAGE AN OBJECT IN SAID BARREL UPON DOWNWARD MOVEMENT OF SAID OPERATOR PISTON RELATIVE TO SAID BARREL, SAID BARREL AND SAID MANDREL HAVING CO-ENGAGEABLE MEANS FOR CONTROLLING MOVEMENT OF SAID MANDREL RELATIVE TO SAID BARREL, SAID BARREL AND SAID MANDREL HAVING MEANS CLOSING THE UPPER END OF SAID UPPER CHAMBER, SAID LAST MENTIONED MEANS OPENING THE UPPER END OF SAID UPPER CHAMBER TO THE EXTERIOR OF THE WELL TOOL UPON PREDETERMINED ROTATIONAL MOVEMENT OF SAID MANDREL RELATIVE TO SAID BARREL TO PERMIT DOWNWARD MOVEMENT OF SAID MANDREL RELATIVE TO SAID BARREL AND SAID PUMP PISTON TO FREE AND GRIPPING MEANS FOR MOVEMENT OUT OF ENGAGEMENT WITH AN OBJECT HELD THEREBY WHEREBY SAID RETRIEVING TOOL IS RELEASABLE FROM AN OBJECT PREVIOUSLY ENGAGED THEREBY. 